US Tax Return Preparation for Expats: Schedule A in the UK

For a high-earning American in the UK, Schedule A beats the standard deduction mainly when US-deductible home mortgage interest is large, because council tax, stamp duty and donations to UK charities are not deductible and UK income tax is usually better credited than deducted. Careful US tax return preparation for expats tests both routes and then traces the result through Form 1116.

At Jungle Tax we prepare both sides of the file: the Form 1040 with its schedules and the UK Self Assessment return. Schedule A is where we most often find a self-prepared return that is arithmetically tidy and technically wrong, usually because US domestic rules were applied to a UK household without adjustment. This guide sets out what each line means for a UK-resident American, what the two returns must show, and where the errors cluster. It is a preparation and compliance guide for the 2025 return (filed in 2026) with the 2026 changes flagged; it is not a planning paper, and figures should be confirmed against your own facts before filing.

Does itemising beat the standard deduction for an American living in the UK?

You claim the larger of the standard deduction or your total itemised deductions. For the 2025 tax year the standard deduction is $15,750 for single filers and married individuals filing separately, $31,500 for married couples filing jointly and $23,625 for heads of household. For 2026 the amounts rise to $16,100, $32,200 and $24,150 respectively.

Those are high hurdles for a UK resident, because the deductions that carry most US-resident households over the line are largely unavailable:

• State and local taxes are usually nil for a long-term UK resident who has properly ended state residence.
• Property tax on the home is council tax, which is not deductible.
• Charitable giving is typically to UK charities, which do not qualify on a US return.
• Medical costs rarely clear the income-based floor where most care is provided by the NHS.

That leaves home mortgage interest as the item that decides the question in most UK cases. A sizeable sterling mortgage on a London home can clear the standard deduction on its own, even after the US debt limit is applied. Without one, itemising seldom wins.

There is a second, less obvious question: does it matter? Where UK income tax exceeds the US tax on the same income and a foreign tax credit already brings the US liability on that income to nil, a larger deduction may change no cash figure at all. It changes the amount of unused credit carried forward instead. Itemising has real cash value where there is US tax that foreign tax credits do not cover, such as US-source income, or income the UK taxes lightly or not at all. A properly prepared return computes both routes and keeps the workings.

Two filing-status points belong here. If you are married filing separately and your spouse files a US return and itemises, you must itemise too, even where the standard deduction would be higher. And the married-filing-separately limits on mortgage debt and state and local taxes are half the joint figures, which matters for Americans married to a non-US spouse who is not treated as a US resident for return purposes.

Is UK mortgage interest deductible on a US tax return?

Yes. The location of the property and the currency of the loan are irrelevant. Interest is deductible on Schedule A where the loan is secured on a qualified home (your main home or one second home) and was used to buy, build or substantially improve it. A UK repayment mortgage, an interest-only mortgage and an offset mortgage can all qualify, although an offset arrangement reduces the interest actually charged and only interest actually paid is deductible. The IRS sets out the rules in Publication 936, Home Mortgage Interest Deduction.

How is the acquisition debt limit measured for a sterling mortgage?

The limit is fixed in dollars. Interest is deductible on up to $750,000 of acquisition debt ($375,000 if married filing separately) for loans taken out after 15 December 2017, and on up to $1,000,000 ($500,000) for older, grandfathered debt. The 2025 legislation made the $750,000 figure permanent.

A sterling balance must therefore be translated into dollars before the limit is tested. Where the average balance for the year exceeds the limit, only a proportion of the interest is deductible: the limit divided by the average balance. Two practical consequences follow.

• The deductible fraction moves with the exchange rate. A £650,000 mortgage is under the limit at $1.15 to the pound and over it at $1.30. The same loan can be fully deductible one year and partly restricted the next.
• The method must be consistent. IRS guidance does not prescribe a specific rate for translating a foreign-currency mortgage balance for this purpose. We apply a reasonable, documented method (typically the same published average rate used for the interest itself) and apply it the same way every year. Treat any single "correct" rate you see quoted as an assumption, not a rule.

Worked illustration

A married couple filing jointly have a £1,400,000 mortgage taken out in 2021, with interest of £63,000 paid in the year. Using an illustrative average rate of $1.30:

• Average balance: $1,820,000. Interest paid: $81,900.
• Deductible fraction: $750,000 divided by $1,820,000, or about 41.2%.
• Deductible interest: about $33,750.

That exceeds the 2025 joint standard deduction of $31,500 by roughly $2,250. Itemising wins, but by far less than the headline interest figure suggests. The return we most often correct is the one that claimed the full $81,900.

How is it reported when no Form 1098 is issued?

UK lenders do not issue Form 1098. The interest is reported on the Schedule A line for home mortgage interest not reported on Form 1098, supported by the lender's annual mortgage statement and your translation workings. The line asking for the recipient's name, address and identifying number is aimed at loans from individuals, such as seller financing; an institutional UK mortgage does not require a US taxpayer number for the lender. Lender arrangement and product fees are a separate question from interest and should not simply be added to the interest line.

The currency issue that sits outside Schedule A

A sterling mortgage is a foreign-currency liability for US purposes. When principal is repaid, whether on redemption, refinancing or sale, and the dollar has strengthened since the loan was drawn, the IRS position is that the difference is taxable exchange gain at ordinary rates. An exchange loss on a personal mortgage is not deductible. This does not appear on Schedule A, but any return that claims UK mortgage interest should have been prepared with the loan's dollar history on file.

Why is council tax not deductible on Schedule A?

Since 2018, US law has denied any itemised deduction for foreign real property taxes that are not paid in a business or income-producing activity, and the 2025 legislation continued that rule without an end date. The IRS Schedule A instructions tell filers not to include foreign personal or real property taxes. Council tax on your home therefore does not belong on the return, whichever way it is characterised: as a foreign real property tax it is barred, and if it is regarded instead as a charge on occupation it is not a deductible tax at all.

Several competitor guides still describe foreign property tax as deductible within the state and local tax cap. That was the law before 2018. It is not the law for the 2025 or 2026 return.

Related UK charges follow the same logic:

• Stamp duty land tax (and the Scottish and Welsh equivalents) is a transfer tax. It is not deductible; it is added to the US cost basis of the home.
• Service charges, ground rent and buildings insurance are personal living costs.
• Council tax on a let property that the landlord bears is different. It is an expense of the rental activity and belongs on Schedule E, not Schedule A.

Should UK income tax be deducted or credited?

Foreign income tax is the one foreign tax that can appear on Schedule A. It goes on the "other taxes" line and, unlike state and local taxes, it is not subject to the state and local tax cap. But it is a choice, made each year, between a deduction on Schedule A and a credit on Form 1116, and the IRS explains the mechanics in Publication 514, Foreign Tax Credit for Individuals.

• The choice is all or nothing for the year. If you credit any qualifying foreign income tax, you must credit all of it. You cannot credit UK tax on salary and deduct UK tax on dividends.
• A credit is almost always worth more. A deduction saves tax at your marginal rate; a credit reduces US tax dollar for dollar, with unused amounts carried back one year and forward ten.
• Tax on excluded income gives neither. UK tax attributable to earnings excluded under the foreign earned income exclusion cannot be credited or deducted.
• The choice can be revisited. A switch from deduction to credit can generally be made on an amended return within ten years of the original due date, which is a common repair on historic self-prepared returns.

The practical point for preparation: UK income tax and National Insurance are not automatically Schedule A items. On most UK-resident returns the "other taxes" line should be empty and the UK tax should sit on Form 1116. Whether National Insurance contributions are creditable at all is a separate technical question that should be settled deliberately, not by default.

How does the state and local tax cap apply to an American abroad?

For 2025 the cap on state and local income, sales and property taxes is $40,000 ($20,000 if married filing separately), rising to $40,400 ($20,200) for 2026. It is reduced by 30% of modified adjusted gross income above $500,000 for 2025 ($505,000 for 2026), half those thresholds for separate filers, but never below $10,000 ($5,000).

For a high earner in the UK three points matter:

• The cap only has something to bite on if US state or local tax is still being paid: a state that continues to treat you as resident, state tax on US-source income, or property tax on a US home kept for personal use.
• Modified adjusted gross income for the phase-down adds back the foreign earned income exclusion. Excluding earnings does not keep you under the threshold.
• UK income tax is not inside the cap, and council tax is not inside it either because it is not deductible at all.

Do donations to UK charities qualify on a US return?

Generally not. A charitable deduction requires the recipient to be a qualifying organisation created or organised in the United States. The US has charitable-deduction provisions in a small number of income tax treaties, but the US-UK treaty is not one of them. A donation made directly to a UK-registered charity is therefore not deductible on Schedule A, however large and however well documented.

What can qualify:

• A donation to a US qualifying organisation that carries out work abroad, provided it retains control and discretion over the funds and the donation is not simply earmarked for a named foreign body.
• A donation to an organisation structured to be recognised in both countries, which can support a US deduction and UK relief on the same payment. The donor's paperwork must then satisfy both systems.

For 2025, US substantiation rules apply in the usual way, including a contemporaneous written acknowledgement for any single contribution of $250 or more. From 2026, itemisers can deduct charitable contributions only to the extent they exceed 0.5% of adjusted gross income, and a separate limited deduction for cash donations to qualifying US charities ($1,000, or $2,000 on a joint return) becomes available to those taking the standard deduction.

What does the UK return show instead?

The UK side works on a different principle. Under Gift Aid, the charity reclaims basic-rate tax on the donation, and a higher-rate or additional-rate taxpayer claims the difference through Self Assessment. HMRC's own example: a £100 donation is worth £125 to the charity, and a 40% taxpayer can claim back £25. The donation must be to a qualifying charity under UK rules, a valid declaration must be in place, and the donor must have paid enough UK tax to cover what the charity reclaims. A donation to a US charity does not attract Gift Aid.

The result is an asymmetry that surprises many dual filers: the same donation is routinely relieved on one return and ignored on the other. The preparation task is to classify every donation by recipient before either return is drafted, not to copy one schedule into the other.

Can UK medical expenses be deducted?

Unreimbursed medical and dental expenses are deductible only to the extent they exceed 7.5% of adjusted gross income. Privately paid treatment, dental work, prescriptions and medical insurance premiums paid personally from taxed income can count, wherever in the world they are incurred. NHS care generates no expense. On an adjusted gross income of $600,000 the floor is $45,000, so the line is relevant mainly in a year of exceptional private medical cost. The UK return gives no relief for personal medical expenses at all.

US and UK treatment compared

Item	US return (Schedule A, 2025)	UK Self Assessment return
Interest on a mortgage over the main home	Deductible on up to $750,000 of acquisition debt ($1,000,000 if grandfathered), measured in dollars	No relief
Council tax on the home	Not deductible	Not deductible
Stamp duty land tax	Not deductible; added to cost basis	No income tax relief
UK income tax	Deduction on "other taxes" line or credit on Form 1116; one choice for all foreign income taxes in the year	The liability itself
US state and local tax	Deductible up to $40,000, reduced above $500,000 of modified AGI, floor $10,000	Not an itemised relief; any credit follows the UK double taxation rules
Donation to a UK charity	Not deductible	Gift Aid; higher and additional-rate relief claimed on the return
Donation to a US charity	Deductible within the percentage limits, if substantiated	No Gift Aid
Private medical costs	Deductible above 7.5% of AGI	No relief

How do itemised deductions feed into the foreign tax credit limitation?

This is the step most often missed, and it is where Schedule A stops being a self-contained form. The foreign tax credit is limited, category by category, to the US tax on foreign-source taxable income. Foreign-source taxable income is gross foreign income less the deductions allocated and apportioned to it, and that includes a share of your itemised deductions (or of the standard deduction, if you take that instead).

• Home mortgage interest has its own line on Form 1116 and is apportioned between US and foreign-source income under a worksheet in the form instructions. Where gross foreign-source income is $5,000 or less, it is allocated entirely to US-source income.
• Deductions not definitely related to any class of income, such as medical expenses and deductible property taxes on a home, are apportioned rateably by gross income.
• Charitable contributions are allocated to US-source income under the regulations, so they do not reduce foreign-source taxable income.

Where all income falls in a single foreign category, the apportionment may make no difference to the result. Where income is mixed, for example UK employment income alongside US-source dividends, or general and passive category income side by side, each deduction apportioned to a foreign category reduces the credit limit for that category. A mortgage interest deduction can therefore reduce taxable income and reduce the allowable credit in the same computation. The saving from itemising is the net of the two, and it can only be seen by running Form 1116 under both routes. Deductions allocable to excluded earned income are a separate adjustment, although personal items such as home mortgage interest and charitable contributions are not treated as definitely related to excluded earnings.

The Form 1116 instructions set out the lines. The point for a high earner is that the question "does itemising beat the standard deduction?" cannot be answered on Schedule A alone.

What changes for the 2026 return?

• Standard deduction rises to $16,100 (single and married filing separately), $32,200 (joint) and $24,150 (head of household).
• State and local tax cap rises to $40,400, with the phase-down starting at $505,000 of modified adjusted gross income.
• A 0.5% of adjusted gross income floor applies to charitable deductions for itemisers.
• A new overall limitation reduces the value of itemised deductions for taxpayers in the 37% bracket, so that the benefit is capped at roughly 35 cents per dollar deducted.
• Qualifying mortgage insurance premiums are again treated as deductible mortgage interest.

These are our reading of current law at the date of publication. The 2026 forms and instructions should be checked when issued, and anything turning on a specific figure should be confirmed before filing.

What must the two returns show?

The US return

• Schedule A, if itemising: mortgage interest on the non-Form 1098 line, restricted where the dollar balance exceeds the limit; any US state and local taxes within the cap; qualifying charitable contributions only; medical expenses above the floor.
• Form 1116 for each income category, with itemised deductions apportioned.
• Consistent exchange rates across Schedule A, Form 1116 and the income lines, with the source recorded.
• A retained comparison of the standard-deduction and itemised results.

The UK return

• Gift Aid donations in the charitable giving section, with any carry-back election made on the original return and not by amendment.
• No entry for main-home mortgage interest, council tax or medical costs.
• Foreign tax credit relief claimed only where the treaty and UK law give the UK the secondary taxing right.

Records to keep

• Annual mortgage statements showing opening and closing balances and interest charged, and the original completion statement showing how the loan was used.
• The dollar value of the loan when drawn and of each principal repayment.
• Donation acknowledgements, sorted by US and UK recipients, and Gift Aid declarations.
• Private medical invoices and insurance premium statements.

Common errors on self-prepared returns

1. Claiming council tax as a state and local or property tax.
2. Deducting donations to UK charities because a Gift Aid receipt exists.
3. Claiming all sterling mortgage interest without testing the dollar debt limit.
4. Deducting UK income tax on Schedule A and also crediting it on Form 1116, or splitting the two within one year.
5. Using different exchange rates on different forms for the same year.
6. Itemising without apportioning the deductions on Form 1116, which overstates the credit.
7. Itemising when the standard deduction was higher, or taking the standard deduction when married filing separately and the spouse itemised.
8. Including stamp duty land tax as a deductible tax.
9. Deducting interest on borrowing secured on the home but used for something other than buying or improving it.
10. Ignoring the foreign earned income exclusion add-back when testing the state and local tax phase-down.

Most of these are corrected by amended returns for the open years. Where the pattern sits alongside unfiled returns or missed foreign account reporting, the route is different and our IRS streamlined filing team will assess whether that procedure fits the facts.

How we prepare Schedule A for UK-resident Americans

Our preparers work from UK source documents: mortgage statements, completion statements, donation records and the UK tax computation. We build the dollar schedule for the loan, compute the US return under both the standard deduction and Schedule A, carry each route through Form 1116, and file the one that produces the correct lower liability, with the comparison retained on file. The UK return is prepared alongside by our UK tax services team so that Gift Aid relief and treaty credits are claimed once and in the right place. Clients with complex income typically come to us through our high net worth practice or as referrals to our US-UK tax accountants.

If you own a UK home with a substantial mortgage, give to charity on both sides of the Atlantic, or suspect that earlier returns claimed council tax or UK donations in error, we can review the position and prepare both returns correctly. To arrange a confidential consultation, contact our cross-border team.